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Author Topic: brain storm an optimal human safety system for back line  (Read 97277 times)

John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #480 on: March 23, 2016, 12:35:26 pm »

It's not gossip if it's demonstrable truth.  That said there is often little productivity in recalling the past with a jaundiced eye - history cannot be changed and any future between most of the parties is unlikely.

I know that my view of Hartley, Inc is based only on my outside observations and the limited contact I had with persons employed there (whose information may have been no better than my own).  John's comment about the executive trade-off of China plant or Crest is one example of battling crystal balls - in the Analog Crystal Ball the purchase of Crest looked good; in the Digital Crystal Ball owning a plant in China looked better.  Ultimately the ACB was playing a re-run while the DCB was receiving a new program, and the Guy Who Decides liked the re-run better.
I try not to share too much inside information but a decade or two later it seems relatively harmless, and perhaps informative to the questions asked. IMO it was an important fork in the road with two distinct paths leading to different potential outcomes. While nobody asked me, i preferred hanging out in NJ where Crest was based and I grew up, to spending time in China. 

JR

PS: I only mentioned UB as shorthand to explain my reluctance to approach Peavey regarding my outlet tester. I expect that suggestion was made at least partly in jest if not wholly.
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Mike Sokol

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Re: brain storm an optimal human safety system for back line
« Reply #481 on: March 23, 2016, 12:42:07 pm »

Guys, even though everyone is playing nicely on this OT swerve, we don't want this thread to turn into personality bashing. Let's move on to technology concerns...
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #482 on: March 25, 2016, 12:41:46 pm »

Guys, even though everyone is playing nicely on this OT swerve, we don't want this thread to turn into personality bashing. Let's move on to technology concerns...
Yes drill sargeant  ;D ;D

It's been a crazy week.. I sold/shipped more drum tuners this week than some recent months but I'd be crazy to complain about that. I'm finally getting caught back up.

I just pulled the trigger on my LAST EVER OD-1 pcb order. This time I paid up for DHL shipping from china so I don't have to wait 3+ weeks.

I need to order a few more SMD parts but they are not a rush...

Back in my early generation PCBs I was able to lay these out single sided with room to spare... now this is one tight puppy using traces on both sides. One big difference is using higher voltage resistors, higher voltage diodes etc. that are physically larger.

more later... another step forward.

JR
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #483 on: April 19, 2016, 08:45:21 pm »

Finished my taxes... back to the bench.

built up 3 tested one.... Happily spanked the 100M insulation test at 500V (Thanks again Rob)  ;D UL kiss my grits.

You can see the cheaper 1W resistor on one board and the more expensive  1/4W on the other.

I didn't order 2 resistor values that I need (dumbass), but they don't impact the testing.

Another big step forward.

JR
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #484 on: April 23, 2016, 02:59:49 pm »

I just ordered 4 new resistor values, so I can get this version rocking ($4. for 400 resistors, the postage will cost more than the parts). 

2 values I forgot to order, one tweak that makes it work better, and another maybe tweak. I have all three boards I built up working, but one resistor with 160V across it is only rated for 75V (150V overload). Next week I'll get it squared away with a 200V part. 

Since the insulation resistance test uses DC I decided to measure it with the voltage polarity reversed... that way it measures even better 160M.

I've got another company I approached about partnering on this ignoring me... (Maybe it's me).  :-\

JR
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Stephen Swaffer

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Re: brain storm an optimal human safety system for back line
« Reply #485 on: April 23, 2016, 11:12:50 pm »

More likely a lack of understanding.  I'm fairly certain a surprisingly high percentage of "licensed electricians" would need more than a few minutes of instruction to understand the benefits-I could name a few in my business area-but won't.  I don't envy anyone trying to explain the benefits to an exec.
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #486 on: April 24, 2016, 11:53:39 am »

More likely a lack of understanding.  I'm fairly certain a surprisingly high percentage of "licensed electricians" would need more than a few minutes of instruction to understand the benefits-I could name a few in my business area-but won't.  I don't envy anyone trying to explain the benefits to an exec.
I'm not sure it is just that, but agreed we need to raise awareness that RPBG can and has killed people, and the widely used 3 lamp tester ignores RPBG, indicating good. I got so tired of explaining it that I published a web page http://circularscience.com/home/terms-and-conditions/od-1

I've been gonged by business executives who understand RPBG, but made the best decision for their company.

The business decision to undertake a new product is not just the simple is it a good idea? A company would have to invest several ten thousand dollars to tool up a custom package (not trivial to pass UL mechanical criteria for plugs). I am finessing the plug design by using an existing UL approved plug.

Then the company would have to execute the circuit design. I can't count how many hours I have invested into this design. I am still learning stuff that isn't in books, or wasn't in books back when I matriculated.

Then get UL to approve. I believe UL is flexible, since they already approve the testers that don't work, but they require lubrication with cash especially to approve a novel approach. I expect an interesting discussion about the safety of my approach, and my intention to not print the caveat as stated in the UL spec.

I asked one non-UL test agency to quote on testing my OD-1 and they declined.  :'(

I've been looking at the existing outlet tester technology, and any that depend on the outlet safety ground as a ground reference will be susceptible to being fooled by RPBG (with AC voltage measurements it doesn't matter which end is hot).  I saw one fancy premium tester that included the UL fine print (code for can't detect RPBG i.e. can't detect two wiring faults at the same time. )

IMO the cheap 3 lamp testers should not even be sold... Nobody reads the fine print caveat printed on the back of the cardboard counter card they are sold with. BTW these testers should say "will not detect potentially lethal wiring".

NCVT are your friend.

JR

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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #487 on: April 27, 2016, 12:58:45 pm »

Oh oh... just changed it again....  :-\

I need to do some more component research but I am now reading 550M insulation resistance, both polarities.  8) 8) I suspect it's higher than that.

I wasted some more time trying to make this work without the touch probe, but still no success.

One more cut...

JR

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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #488 on: April 30, 2016, 11:50:45 am »

"I had a dream......".  I had a lucid dream the other night about designing an outlet tester that didn't require a touch contact (external reference). After solving that design problem I fell into a deep sleep... I woke up the next morning, and like every other morning, it doesn't work with simple discrete components.  :'(

It is an unfortunate characteristic of AC voltage/current, that when measuring with a meter relative to the two leads, polarity doesn't matter.  You could swap the two meter leads around and get the exact same reading. This is why the cheap 3-lamp outlet testers are so easily fooled.

RPBG is not the only erroneous reading they make, but perhaps the most hazardous to human safety. I need to test more combinations and put a chart on my OD-1 page. If I was tasked with designing an outlet tester and that 3-lamp approach was the best I could come up with, I'd drop the project and tell my boss that it can't be done.  8)

I don't completely understand why UL approved it, with such a minimal warning notice. I would have made them print a skull and cross bones on the front of the 3-lamp tester housing.

JR
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Jonathan Johnson

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Re: brain storm an optimal human safety system for back line
« Reply #489 on: May 01, 2016, 01:52:36 am »

"I had a dream......".  I had a lucid dream the other night about designing an outlet tester that didn't require a touch contact (external reference). After solving that design problem I fell into a deep sleep... I woke up the next morning, and like every other morning, it doesn't work with simple discrete components.  :'(

I have no idea HOW it works, but I have just such an NCVT. I can stab the plastic tip into the hot side of an outlet, let go, and it stays lit.

I have had it for probably 25 years. It was sold by GB (then known as Gardner-Bender). It uses two AA batteries, and I've changed them maybe twice in that time.
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Stop confusing the issue with facts and logic!
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